I was wondering if it's possible to embed HTML files into DITA XML directly from Github, so that the content of the HTML files would be shown in the XHTML deliverable of the DITA file - preferably inside a <codeblock> element. We would like to demonstrate our front-end files in our documentation, and by doing it like this, the demonstration files would always stay up-to-date, because they'd be served from their original source.

I tried playing with the <object> element, but I only managed to create a link to the file in Github. I also tried Gist-it http://gist-it.appspot.com/, but couldn't figure out, how to get the Javascript to print anything in the resulting XHTML file.

A problem would be that the DITA Open Toolkit publishing engine does not retrieve contents from resources other than local files on disk.But if you are running the transformation from Oxygen and you edit the transformation scenario, there is a parameter called fix.external.refs.com.oxygenxml which can be set to yes in order to make this work.